All's quiet at sea during shark expedition

Michael McCallister, a fisheries scientist from the University of North Florida in Jacksonville, believed he might have a chance to use his ultrasound wand Tuesday, running it down the sides of a pregnant great white, hoping for a glimpse of her pups.

CHATHAM — Michael McCallister, a fisheries scientist from the University of North Florida in Jacksonville, believed he might have a chance to use his ultrasound wand Tuesday, running it down the sides of a pregnant great white, hoping for a glimpse of her pups.

Instead, McCallister wielded a modified roofing tool pulping sardines in a 5-gallon bucket, turning them into brown mush that he emptied into a barrel of fish heads. Seawater sluiced through the barrel and emptied into the sea creating a slick of fish oil and bits that fanned out behind the stern of the 167-foot modified Alaskan crab boat OCEARCH.

Chum is used to attract sharks so that they can be caught, but Tuesday was the 10th day of fishing on the great white shark expedition off Chatham without catching one of the large predators that hunt the seals that frequent the Northeast's largest gray seal colony. The OCEARCH has been anchored within sight of Monomoy for more than two weeks, astride what scientists hoped was a great white shark highway.

Expedition leader Chris Fischer pointed to an orange buoy that marked the submerged receiver that had recorded the most frequent hits from acoustic tags on great whites.

"We're following the data," Fischer said. Although they had encountered 10 white sharks, they proved to be picky eaters.

"They don't want anything to do with the bait," Fischer said, before stepping off the mother ship onto a 28-foot vessel that would search for sharks closer to shore.

The OCEARCH expedition, which is funded mainly by Caterpillar Tractors, has had success elsewhere. In 2011, they tagged more than 40 great whites off South Africa. Last winter, they placed electronic trackers on one shark near Jacksonville, Fla., and two in Chatham last summer.

But the Chatham sharks were not attracted to baited hooks and were hooked by hand as they passed the boat. In retrospect, Fischer felt he may have misjudged his success in other countries where cage diving is allowed and is prevalent and where sharks are accustomed to having bait and chum in the water.

"It's like ringing a dinner bell," he said.

Fischer still has plenty of time with three weeks remaining on the permit that allows him to catch and tag sharks in state waters. And he wouldn't rule out the option of asking for an extension to the permit.

Fischer's approach is unique and represents an attractive research possibility, said scientists on board the OCEARCH. The smaller vessel also spreads chum on the water and drifts along the shore hoping that the fish oil slicks from the two vessels, along with the natural plume of feces and other bodily waste emanating from the seal colony, will attract great whites to the area to the large hooks baited with tuna. The specially crafted hook is bent back in a circular shape with a barbless tip that tends to snag in the jawline, making it easy to remove.

Once hooked, the smaller vessel guides the shark over to a special hydraulic platform on the crab boat that is capable of lifting the big fish out of the water. Scientists have only a 15-minute window before the shark is lowered back into the sea. Hoses pump water into the white shark's mouth and over its gills, and a dark towel is placed over its eyes. This calms the animal even while blood is being drawn and tissue samples taken, said Massachusetts state shark researcher Greg Skomal, although scientists are not sure why.

A team of researchers from all over the country, operating with the efficiency of a pit crew, swoop in and attach nearly $12,000 in sophisticated electronic tags and take blood, tissue and other biological samples, and do an ultrasound that will help determine whether the shark is pregnant or ovulating, what it eats, and the level of contaminants like mercury it has absorbed from its prey.

For scientists who spend the majority of their careers studying this large predator from afar, the opportunity for a hands-on experience is intoxicating. Most large shark research is limited to tagging studies and examination of dead animals.

A live great white, whose physiology can be examined through tissue, blood and other samples, and whose movements can be tracked both long term and in detail for a short time period by attaching a variety of electronic devices, gives scientists a three-dimensional picture.

Mote Marine Laboratory researcher Nick Whitney wants to fix an accelerometer on the next six sharks OCEARCH catches. The device measures the position of the great white in the water, whether he is facing down or up, is twisted or tilted, and can only be attached to animals that are out of the water. While the first three devices he fixed to OCEARCH sharks last year helped determine that the animals quickly resumed normal swimming, Whitney has a greater goal — he would like to see his instrument record the distinct positions great whites assume while mating. And he, like other scientists, wonder if the Cape might be a shark breeding ground.

While the wait can be monotonous, with scientists working on research papers and taking care of administrative duties, it can have unexpected benefits, said Michael Berumen, a scientist at the Red Sea Research Center in Saudi Arabia who specializes in whale sharks. The shark research community is small and their work somewhat similar. Downtime on a ship often leads to problem solving.

Like most scientists on the ship, Berumen understands the unpredictability of nature and that failure comes with the territory.

"Every scientist wants to do their best to find targets, but the sea is big," he said.